In the standard of q355b square tube, most of them specify tensile test and hardness test at the same time. For those materials that are not convenient for hardness test, such as q355b square tube, only tensile test is specified. In particular, stainless steel strip and q355b square tube as thin as 0.05mm, which makes it easy to solve the problems that were difficult to solve in China in the past.
The analytical technology of square tube sizing rolling. When sizing rolling is adopted, because there is no tool on the inner surface, the shape of the inner surface of the rolled material is not neat when rolling the tube. When the roll mill is used, the inner surface of the rolled material is angular. The occurrence mechanism of this phenomenon and the countermeasures to be taken are clarified by using the three-dimensional finite element method.
Naranjo.The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, square rectangular tube, seamless square tube, galvanized square tube, galvanized tube, high price service, on-site settlement, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R2. The diameter of the reinforcement to be straightened is D, and the center distance between them is adjusted to R1 + R2 + D.
The butt joint between the head and tail of square pipe and strip steel adopts single wire or double wire submerged arc welding, and automatic submerged arc welding is adopted for repair welding after rolling into square pipe.
.The test can be carried out under cold and hot conditions. If the test temperature is not specified, the test shall be carried out under normal temperature, but not lower than - 10 ℃.
Square pipe, also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe for short. The allowable deviation of wall thickness of square pipe is f and J q355b respectively. When the wall thickness is no more than 10mm, it shall not exceed plus or minus 10% of the nominal wall thickness. Long term square pipe, rectangular pipe, seamless square pipe, galvanized square pipe, galvanized pipe, 20-year-old brand, price advantage and quality guarantee! When the wall thickness is greater than 10mm, it is plus or minus 8% of the wall thickness, except for the wall thickness of corners and weld areas.
Square tube saves raw materials: the material rate of cold parts can usually reach more than 80%. For example, the material rate of pin cutting of brand automobile is 43%, while the material rate when cold is used is increased to 92%; For another example, after the universal joint bearing sleeve is changed to cold, the material rate is increased from 28% in the past to%. It can be seen that the use of cold production of mechanical parts can save a lot of steel and non-ferrous metal materials.
Solid bending, as the name suggests, is to compact the bending. During real bending the inner and outer rollers and the inner and outer walls of the pipe blank are compacted in both directions.
Main uses of square tube: square tube is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, but the ring heating furnace is mainly used. The heating furnace has an annular furnace bottom, which can rotate slowly, the blank is loaded along the diameter direction of the furnace bottom from the inlet, and can be heated and homogenized to the specified temperature when it is used at the outlet. The production process of seamless square tube is relatively slow, and the heating operation especially needs patience. Because if the heating operation is not standardized, cracks, folding and eccentricity on the inner or outer surface of the tube blank will only produce waste products and defective products.
Installation conditions.After time, the workpiece forms an oxide film with a fixed thickness and presents various colors. Chemical oxidation method is to form various film colors in a specific solution at temperature and time; Because of the law & rdquo; More, the reference electrode must be used. Electrochemical method is to form the color of chloride film with fixed thickness in specific electrolyte at temperature voltage and time. This process is mature and widely used. Ion implantation method is to vaporize ions in vacuum and deposit them on the surface of q355b square tube, such as watch case on the market. The golden color of watch strap adopts this process technology, which is suitable for mass production. The process of gas phase cracking is more complex and less used in industry. Square tube has long been widely used in mechanical industry. When the square pipe is cut automatically, when the square pipe is hoisted to the gas cutting platform, the distance difference between the two ends of one side of the pipe and the guide rail shall be adjusted within 5mm. During semi-automatic cutting, the guide rail shall be placed on the plane of the cut pipe, and then the cutting machine shall be placed on the guide rail gently.
At present, researchers at home and abroad have carried out experimental discussion on the anti adhesion of square tube surface. So far, there is still a lack of research on surface adhesion, there is no systematic and perfect theory to guide the preparation of anti adhesion inner surface of pipeline and there is a lack of operable and low-cost inner surface preparation technology of square pipe. In terms of solid surface adhesion mechanism, based on the solid-liquid interface adhesion work theory and smooth solid surface model, this paper analyzes the spreading process on machined rough surface, studies the dynamic movement characteristics of solid-liquid vapor phase line, directly analyzes the adhesion process, and establishes a line spreading model based on small system energy, It provides theoretical guidance for the preparation of anti adhesion surface of pipeline.
In the heat exchange planning of metallurgy, petrochemical and other occupations, there are various forms of heat exchangers, but the conventional heat exchangers have many disadvantages, such as poor heat exchange, difficult cleaning large dust thermal resistance and so on, which can not meet the needs of production customers. The square tube heat exchanger based on square tube throat has the advantages of excellent heat exchange, easy cleaning, small dust thermal resistance and compact structure.
With the progress of the times, square tubes are used in more and more fields, and their scope of use is obviously increasing, we need to store square tubes reasonably. Customers should also learn to arrange reasonably when storing square tubes. Let's understand how to store square tubes correctly.
project.Material classification: square pipe is divided into ordinary carbon steel square pipe and low alloy square pipe.
High density may not be obtained by simple pressurization, and insulation shall be carried out at the same time.
After the sample is flattened to the specified flattening distance h, remove the load and remove the sample.
Naranjo.After RH treatment, the molten steel should be fed with Si Ca line when the molten steel temperature is high. At this time, calcium treatment can reduce sulfur segregation in the later solidification process.
Before gas cutting, remove the dirt and grease on the steel surface, and leave a certain space below to facilitate the blowing out of slag. During gas cutting, the movement of the cutting torch shall be kept at a uniform speed. The cutting surface should be 2 ~ 5mm away from the tip of the flame core. If the distance is too close, and if it is too far away, the cutting will be interrupted easily due to insufficient heat.
When processing the square tube, some processes need to heat the seamless square tube. The heating operation in the processing of the seamless square tube plays a very key role in the quality of the finished seamless square tube.